Lamp-socket.



0. wmsrom. LAMP SOCKET.

APPLICATION FILED JUNE 8.19M.

' Patented Mar. 19, 1918.

W/ TNESSE' $5M 1- 4 m/W MV fi l FEQE.

LAMP-SOCKET.

Specification of Letters Patent.

Application filed June 8, 1916. Serial No. 102,440.

To all whom it may concern:

Be it known that I, OvnnroN WINSTON, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of M'nnesota, have invented certain new and useful Improvements in Lamp- Sockets; and I do hereby declare the following to he a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My present invention has for its object to provide an improved lamp socket, and to such ends, generally stated, the invention consists of the novel construction and combination of parts hereinafter described and defined in the claims.

Particularly, the invention has for its object to provide a simple and eiiicient means for effecting various adjustments of a twofilament light bulb, or other light bulbs having filaments that should always be set vertically, or in a predetermined position. The chief feature of the invention is directed to a simple and efiicient expedient for accomplishing these results.

This expedient consist preferably in providing the interior of the so-called lamp holding socket with spirally arranged notches for engagement with the lock lugs on the shank of the light bulb.

In the accompanying drawings which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Figure 1 is a view chiefly in vertical section with some parts shown in full, illustrating the improved socket;

Fig. 2 is a side elevation of the light bulb showing the same on a much smaller scale than in Fig. 1;

Fig. 3 is a section taken approximately on the line 00 m of Fig. 1; and

Fig. 4 is a longitudinal section on the line 410 m of Fig. 3.

The electric light bulb 1, as already stated, may be of the one filament .or two filament type, but as shOWn, it 1s of the two-filament type having an axial filament 2 and an offset filament 2 As is well known, this type of bulb has an outer metallic contact sleeve 3 provided with diametrically opposite lock lugs l and adapted to be telescoped nto a holding" colla 5 that is provided with an externally threaded eccentric portion 5 screwed into the internally threaded socket sleeve 6. Also, the shank of the bulb 1 is provided with an axial contact 3 and an annular contact 3". The three contacts 3, 3 and 3 are insulated from each other by the insulating material of the bulb shank. At its inner end, the eccentric portion 5* of the holding'collar is provided with a rigidlyv secured centering ring 5 of insulatlng material. Rigidly secured in the rear end of the socket sleeve 6 is an insulating block 7, preferably having a forwardly projected axial boss 8. Projecting axially from the insulating block 7 is a forwardly springpressed contact plunger 9 that makes contact with the axial contact 8* of the lamp socket.

The numeral 10 indicates a coiled spring, the

rear end of which surrounds the boss 8 and is anchored against the insulating block 7, and the front end of which is in electrical contact with the annular contact 3 of the lamp socket. The centering ring 5 holds the spring 10 properly centered, out of contact with the metal walls of the holding collar and its eccentric. The above noted elements 5, 9 and 10, in practice, constitute parts of a three-lead circuit.

The holding collar 5 has internal longitudinal grooves 11,through which the lock lugs 4; on the lamp socket sleeve 3 are adapted to be slid into and out of the socket. At the inner extremities of these grooves 11, the collar 5 is formed with spiral or oblique shoulders having circumferentially spaced notches 12 with which the said lock lugs 4 are adapted to be engaged by turning the bulb in respect to the collar, while its shank is inserted into the latter. The pressure of the contact spring 10 and of the spring pressed contact plunger 9 serve normally to hold the lock lugs 4c engaged with the notches 12 into which they are set, and the said bulb can be rotated in respect to said collar, only when it is pressed inward in respect thereto, far enough to disengage the said lugs from said notches.

By rotary adjustments of the collar 5 and its eccentric 5 the bulb may be adjusted both longitudinally of the axis of the redoctor and of the socket sleeve 6 and transversely of said axis. It will frequently happen that the filaments of the bulb will be warped out of proper position. For example, it has been found that the so-called main or axial filament of the bulb will sel- Patented Mar. 19, 1918. p

Y movement.

dom be at the axis of the reflector, but will usually be warped to one ide thereof. A filament thus warped can be set approximately at the axis of'the reflector simply by rotating the bulb within the holding collar until the proper position is reached. WVhen this adjustment has been effected, the bulb,

may be adjusted longitudinally ofthe axis of the reflector until the hot spot of the filament is brought either to the focal center or in any desired position, in respect to the focal center in direction longitudinally of the axis, but in accomplishing this latter adjustment, it will usually happen that with a twoefilament bulb, the two filaments will not be vertically, one over the other, or with a single filament bulb, with transverse fila- 1nent,such filament will be set obliquely, or out of vertical position. Of course, by then turning the lamp holding collar and its eccentric and the bulb together, the said filaments may be brought very close to vertical position, say within the distance between notches 12, and then the said filaments may be vertically positioned, simply by rotating the bulb in respect to the holding collar and eccentric and engaging its lugs 4 with notches 12, either at one side or the other of those previously engaged, according to whether the bulb should be adjusted forwardly or rearwardly in order to set the hot spot of its filament at the exact desired point longitudinally of the axis of the reflector, and in respect to the focal center of the reflector.

Otherwise stated, the spiral or oblique arrangement of the notches 12 will compensate, in the light bulb, for axial movements necessarily given to the holding collar 5 in rotating the same to bring the lamp approximately to proper verticalposition, and the slight rotary adjustment required to move the light bulb lugs from one notch to another in correcting the axial position, will not offset the hot spot of the filament perceptibly from its proper position inrespect to the axis of the reflector. For example, movement to a fourth notch would not require more than a one-fourth rotation of the bulb, and would have the same effect in longitudinal adjustment as a complete rotation of the eccentric. Furthermore, by increasing the pitch or spiral trend of the notches, the longitudinal or axial adjustmentgiven to the bulb by rotation would be further increased in respect to the rotary In the above description it is assumed that the longitudinal advance between adjacent notches 12 is about one-fourth of the pitch between the eccentric and sleeve.

It is important to here note that the notched shoulders 12 have the same spiral trend'and that in each notch ofthe one spiral shoulder, there, is a diametrically opposite of'the threads of the threaded engagement.

notch in the other spiral shoulder. Otherwise stated, the rearmost notch of the one shoulder is diametrically opposite to the rearmost notch of the other spiral shoulder, and the same is true, in respect to themost forward notches of the said two shoulders. This affords the required diametrically op- 'posite notches for diametrically opposite lugs' on the shank of the lightbulb.

Rather coarse threads are desirable for the connection between the eccentric and sleeve 6,'-b'oth because the adj ustmentis more on the eccentricgis used, ,thenecessity for the oblique notches is decreased, but in practice, they are desirable in most instances, and especially where very close adjustment of the bulb, in respect to the reflector, is desired.-

The bulb illustrated has two lock notches, and consequently, there are two series of spirally arranged notches in the holding collar. Some light bulbs are provided with three lock lugs, and for such an arrangement, as is evident, three sets of oblique notches in the holding collar will be desirable.

What I claim is:

1. A lamp holding-socket omprising relatively fixed and movable sections. having screw-threaded engagement, and a light bulb connected to said relatively movable section both for axial and rotary, adjustments therein. 7

2.-A lamp socket comprising relatively fixed and movable sections, one'thereof having screw-threaded engagement with the other, said relatively movable section having a lamp receiving socket formed with longitudinal internal grooves for the-passage therethrough of lock lugs on the lamp stem, and provided'at the inner extremities of said longitudinal grooves with spirally disposed notches with which the said lock lugs are engageable.

3. A lamp socket comprising relatively fixed and movable sections, one thereof having screw-threaded engagement with the other, said relatively movable 'section having longitudinal grooves with spirally disposed notches with which the said lock lugs are engageable, and yielding devices within said socket tending to hold said lock lugs engaged with said lock notches but permitting oisengagement thereof.

4. A lamp socket comprising relatively fixed and movable sections, one thereof having an eccentric portion connected to the other section by threaded engagement, said eccentric bearing member having a lamp receiving socket provided with means for holding the stem of a light bulb with freedom for both axial and rotary adjustments.

5. A lamp socket comprising an internally threaded socket sleeve, and a lamp holding collar having an externally threaded eccentric screwed into said sleeve, said collar having internal longitudinal grooves through which the lock lugs on the stem of a light bulb may be inserted, and having at the inner extremities of said grooves spirally dis- Gopies of this patent may be obtained for posed lock notches with which the lock lugs on said bulb stem may be engaged.

6. A lamp socket comprising an internally threaded socket sleeve, and a lamp holding collar having an externally threaded eccentric screwed into said sleeve, said collar having internal longitudinal grooves through which the lock lugs on the stem of a light bulb may be inserted, having at the inner extremities of said grooves spirally disposed lock notches with which the lock lugs on said bulb stem may be engaged, and a spring-pressed contact within said socket tending to hold said lock lug engaged with said lock notches but permitting disengagement thereof.

In testimony whereof I afix my signature in presence of two witnesses.

OVERTON WINSTON.

Witnesses:

BERNICE Gr. WHEELER, HARRY D. KILGORE.

five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

